The court had heard from Gavin Millar QC, for The Sunday Telegraph, that the injunction breached Mr Booker’s right to freedom of speech and that reporting on the case was in the public interest.

He also argued that reforms brought in to open up the family courts had been ineffective, because although the press were now able to attend hearings, what they were allowed to report was limited.

They were also, in many cases, unable to see court documents, which were key to understanding proceedings.

Mr Millar said: “We could have a discussion about how those reforms have worked and how the press have been helped by them. There’s a general feeling that they haven’t been helped that greatly. Very often they can’t report what they want to report.”

The injunction was imposed after Mr Booker wrote a series of articles about the case, which involved the divorce of the parents of young children.

The mother was placed under an order that prevented her from moving from the address where she and her children live, near the father’s home, to enable him to keep in touch with his children.

It meant she was twice unable to hold down well-paid jobs in the finance industry, because the jobs were too far away for her to commute to.

Before another hearing, the barrister chosen to represent the mother decided that she was suffering from a psychological condition and said the mother was not “mentally competent” to instruct her.

As a result, the barrister said she was not willing to put forward the arguments the mother wished to be put forward in court. She asked to represent herself but it was only after a psychologist gave evidence that she was mentally competent that she was allowed to do so.

Mr Millar argued that journalists should be able to shed light on such legal practices.

He said: “The core of the article was about an episode in the life of a litigant which is certainly an issue of public interest: that the law could operate in that way, that the lawyers representing you could bring into question your mental capacity.”

Mr Booker has written a series of articles highlighting the most controversial aspects of the family courts.

He called the injunction “far too sweeping in its implications” and said the decision to lift it was “a victory for common sense and the rule of law”.

He added: “Had this ruling been upheld, it could have greatly extended the rules of secrecy which govern cases involving social workers, children and the courts, and severely curtailed even such limited freedom as the press still has to report such cases.”

Julia Varley, a solicitor for David Price Solicitors and Advocates, which represented The Sunday Telegraph, said: “It is important that the public are able to receive information about what goes on in the family courts and that the media are able to report on such cases, which are often held behind closed doors.

“This decision is a further step in favour of transparency in the family courts.”

Mr Justice Mostyn’s lifting of the injunction is the latest in a series of rulings intended to open up the courts.

Family courts in particular have often been accused of a lack of transparency because cases involving children are not open to the public. The courts argue that this is to protect the identity of the children, but critics have highlighted the difficulties of reporting on such cases.

In 2008, Jack Straw, the then justice secretary, promised to shed light on family courts and brought in new rules allowing journalists to attend.

But judges ruled proceedings would still be held in private and journalists would therefore be unable to report anything on the case unless the court gave specific consent.

Lord Justice Munby, President of the Family Division of the High Court, has called for greater transparency, calling for “radical and comprehensive reform” of the family court system.